Hanoi_Tower/hanoi.py

233 lines
6.4 KiB
Python

# -*- coding: utf-8 -*-
"""
Created on Sat Apr 25 21:18:50 2020
@author: cpan
"""
import tkinter as tk
import time
gbl_num_disks = 3
GAP = 2
CANVAS_W = 500
CANVAS_H = 400
gbl_speed = 0.001 # in seconds
gbl_step = 2
gbl_pegs = []
gbl_pegstate = [[], [], []]
gbl_disks = []
gbl_tkroot = tk.Tk()
gbl_tkroot.title('Hanoi Tower')
gbl_canvas = None
gbl_ready = True
def setup_gui():
global gbl_canvas
def ent_return(event):
event.widget.tk_focusNext().focus()
def get_ent_focus(event):
global gbl_num_disks
try:
new_num = int(ent_disks.get())
gbl_num_disks = new_num
draw_init_setting()
except Exception as err:
ent_disks.delete(0, tk.END)
ent_disks.insert(0, str(gbl_num_disks))
print(repr(err))
# print(gbl_num_disks)
# options row
tk_row = tk.Frame(gbl_tkroot)
tk.Label(tk_row, text="No. of Disks: ").pack(side=tk.LEFT)
ent_disks = tk.Entry(tk_row, width=5)
ent_disks.insert(0, str(gbl_num_disks))
ent_disks.bind('<Return>', ent_return)
ent_disks.bind('<FocusOut>', get_ent_focus)
ent_disks.pack(side=tk.LEFT, padx=5)
btn_start = tk.Button(tk_row, text="Start", width=6, command=run_hanoi)
# btn_start.bind('<ButtonRelease-1>', run_hanoi)
btn_start.pack(side=tk.LEFT, padx=5)
btn_reset = tk.Button(tk_row, text="Reset", width=6, command=reset_hanoi)
# btn_reset.bind('<ButtonRelease-1>', reset_hanoi)
btn_reset.pack(side=tk.LEFT, padx=5)
tk.Label(tk_row, text="Speed: ").pack(side=tk.LEFT)
tk_var = tk.StringVar(gbl_tkroot)
tk_var.set('normal')
tk_opt_menu = tk.OptionMenu(tk_row, tk_var,
*{'slow', 'normal', 'fastest'})
tk_opt_menu.config(width=6, takefocus=True)
tk_opt_menu.pack(side=tk.LEFT)
tk_row.pack(side=tk.TOP, pady=5)
# animation canvas
gbl_canvas = tk.Canvas(gbl_tkroot, width=CANVAS_W, height=CANVAS_H)
gbl_canvas.pack()
btn_start.focus_set()
gbl_tkroot.lift()
gbl_tkroot.focus_force()
def change_speed(*args):
global gbl_speed, gbl_step
speed_opt = {'slow': 0.001, 'normal': 0.001, 'fastest': 0}
step_opt = {'slow': 1, 'normal': 2, 'fastest': 1}
gbl_speed = speed_opt.get(tk_var.get())
gbl_step = step_opt.get(tk_var.get())
# print(gbl_speed)
tk_var.trace('w', change_speed)
def run_hanoi():
global gbl_ready
# t0 = time.time()
if gbl_ready:
gbl_ready = False
try:
hanoi(gbl_num_disks-1, 0, 1, 2)
except Exception as err:
print(f'forced reset: {repr(err)}')
else:
pass
# t1 = time.time()
# print(t1-t0)
def reset_hanoi():
draw_init_setting()
def draw_init_setting():
global gbl_pegs, gbl_disks, gbl_pegstate, gbl_ready
gbl_pegs = []
gbl_pegstate = [[], [], []]
gbl_disks = []
gbl_canvas.delete('all')
# draw the three pegs a, b, c
peg_w = 10
peg_h = CANVAS_H // 2
peg_dist = CANVAS_W // 3
x1, y1 = (peg_dist - peg_w) // 2, CANVAS_H // 3
x2, y2 = x1 + peg_w, y1 + peg_h
for i in range(3):
gbl_pegs.append(gbl_canvas.create_rectangle(x1, y1, x2, y2, fill = 'black'))
x1 += peg_dist
x2 += peg_dist
gbl_tkroot.update_idletasks()
gbl_tkroot.update()
# create disks on the first peg
disk_h = peg_h // 16
disk_maxw = peg_dist * 2 // 3
disk_minw = 2 * peg_w
x1, y1 = (peg_dist - disk_maxw) // 2, y2 - disk_h - GAP
x2, y2 = x1 + disk_maxw, y1 + disk_h
dx = (disk_maxw - disk_minw) // (2 * max(1, gbl_num_disks-1))
dx = min(dx, 2 * peg_w)
for i in range(gbl_num_disks):
gbl_disks.insert(0, gbl_canvas.create_rectangle(x1, y1, x2, y2, fill = 'red'))
gbl_pegstate[0].append(gbl_num_disks - i - 1)
x1 += dx
x2 -= dx
y1 -= disk_h + GAP
y2 -= disk_h + GAP
gbl_tkroot.update_idletasks()
gbl_tkroot.update()
gbl_ready = True
def move_disk(i, a, b):
global gbl_pegstate, gbl_canvas
disk_num = gbl_pegstate[a].pop()
if disk_num != i:
raise RuntimeError(f'Trying to move disk piece #{i} from peg {a}\
to peg {b} that does not exist.')
disk = gbl_disks[i]
# Lift the disk above peg a
px1, py1, px2, py2 = gbl_canvas.bbox(gbl_pegs[a])
while True:
x1, y1, x2, y2 = gbl_canvas.bbox(disk)
if y2 < py1:
break
gbl_canvas.move(disk, 0, -gbl_step)
gbl_tkroot.update_idletasks()
gbl_tkroot.update()
time.sleep(gbl_speed)
# Move to peg b
px1, py1, px2, py2 = gbl_canvas.bbox(gbl_pegs[b])
new_center = (px1 + px2) // 2
x1, y1, x2, y2 = gbl_canvas.bbox(disk)
center = (x1 + x2) // 2
while center < new_center:
gbl_canvas.move(disk, gbl_step, 0)
gbl_tkroot.update_idletasks()
gbl_tkroot.update()
time.sleep(0.7*gbl_speed) # faster
x1, y1, x2, y2 = gbl_canvas.bbox(disk)
center = (x1 + x2) // 2
while center > new_center:
gbl_canvas.move(disk, -gbl_step, 0)
gbl_tkroot.update_idletasks()
gbl_tkroot.update()
time.sleep(0.7*gbl_speed) # faster
x1, y1, x2, y2 = gbl_canvas.bbox(disk)
center = (x1 + x2) // 2
# Drop down
disk_h = y2 - y1
new_bottom = py2 - disk_h * len(gbl_pegstate[b]) - GAP
while True:
x1, y1, x2, y2 = gbl_canvas.bbox(disk)
if y2 >= new_bottom:
break
gbl_canvas.move(disk, 0, gbl_step)
gbl_tkroot.update_idletasks()
gbl_tkroot.update()
time.sleep(gbl_speed)
gbl_pegstate[b].append(i)
def hanoi(n, a, b, c):
'''
Hanoi algorithm: move n pieces from a to c, using b as buffer.
For each move, call animate() to show the move
'''
if n < 0:
return
hanoi(n-1, a, c, b)
move_disk(n, a, c) # move nth piece from peg a to peg c
hanoi(n-1, b, a, c)
def main():
setup_gui()
draw_init_setting()
# input("Press Enter to continue")
# try:
# hanoi(gbl_num_disks-1, 0, 1, 2)
# except Exception as err:
# print("aborted: " + repr(err))
gbl_tkroot.mainloop()
if __name__ == "__main__":
main()